Whey cryoconcentration and impact on its composition

Whey is a source of food ingredients of high nutritive value. Quality of proceeded whey components depends on the type of the process used and the operation conditions. In this paper, a new method for whey concentration was developed and impact on the physicochemical properties of the final product was studied. Whole cheese whey was concentrated by a cryoconcentration method. A freezing process was carried-out at - 10 +/- 1, -20 +/- 2 and -40 +/- 2 degrees C and the defrosting procedure at 18 +/- 2 degrees C. The procedure was achieved in five levels (stages). Each concentrate of a preceding level (stage) was used as initial solution for the following cryoconcentration stage. The concentrated and ice fractions were analyzed at each cryoconcentration level (stage). It was possible to concentrate the whey up to 35% of dry matter after four levels. Total proteins were concentrated up to 20% of the total dry matter. Lactose was found to be more concentrated in the ice fraction, whereas the proteins were more concentrated in the unfrozen (defrosted, cryoconcentrated) fraction. Concentration efficiency of the process decreased by increasing the cryoconcentration level (stage). Ice recycling seems to be possible to improve the process efficiency. Process optimization by a mathematical modeling showed that the optimum cryoconcentration level (stage) is 3. (c) 2007 Elsevier Ltd. All rights reserved.